1. Field of the Invention
The present invention relates to a lens meter for measuring optical characteristics of a subject lens to be measured.
2. Description of Related Art
In recent years, a lens meter has been proposed which can measure optical characteristics such as refractive power distribution in a wide range of a subject lens to be measured such as a progressive power lens at a time. For example, proposed is a lens meter which projects a number of convergent light bundles onto the subject lens using one light source and a microlens array with a number of microlenses, and measures the refractive power distribution based on a shift amount of positions of the light bundles passed through the subject lens (refer to Japanese Patent Application Unexamined Publication No. Hei9-33396).
However, the microlens array is high in cost. Moreover, in an optical system using the microlens array, a complicated configuration is required for selectively projecting the convergent light bundles through the microlenses onto the subject lens or for compensating for insufficiency of its light amount.